Preparation And Photocatalytic Performance Of Ti-Containing Ternary Hydrotalcite Composites

In recent years,photocatalytic technology has been widely used in water treatment because of its high efficiency,low energy consumption,low cost and low pollution.It is the focus and difficulty of photocatalytic research to develop new and efficient photocatalytic materials.The hydrotalcites and its calcined product are used as photocatalysts to treat wastewater,which not only does not cause secondary pollution,but also has strong degradation ability and can effectively remove pollutants in water.Co/Ti/Fe ternary hydrotalcite was prepared by coprecipitation method and calcined to obtain the product,then its catalytic performance were investigated.The main research results are as follows(1)The optimum preparation process of ternary hydrotalcite containing Ti and its calcined products is as follows:molar ratio of Co/Ti/Fe is 1:2:1,and the co-precipitator should choose the mixed solution of NaOH and Na2CO3;the calcination condition is 450 ?,and the calcination time is 2 h.After calcination,the original layered structure of hydrotalcite-like materials is changed,and the pore size range becomes larger,which helps to improve the photocatalytic performance.The two hydrotalcite-like photocatalysts prepared show excellent ultraviolet absorption performance,and the light absorption intensity of calcined Ti-LDO is better.(2)The experimental results show that the optimal conditions forphotocatalysis of Ti-LDH should be:initial concentration of solution 20mg/L,pH=2,dosage of Ti-LDH is 0.07g,reaction under optimal conditions,simulated dye wastewater The removal rate of methylene blue(MB)solution can reach 75.11%:the optimal conditions for Ti-LDO photocatalysis experiment should be:initial concentration of solution 15mg/L,pH=4,dosage of Ti-LDO is 0.05g,under optimal conditions The reaction rate of MB is up to 97.31%;this also proves that the photocatalytic performance of Ti-LDO is better than that of Ti-LDH.(3)Under the irradiation of ultraviolet light,the photocatalytic reaction of the Ti-LDH containing Ti ternary hydrotalcite and its calcined product Ti-LDO on the MB is consistent with the LH first-order kinetic model;Experiments show that photogenerated holes and hydroxyl radicals are active groups involved in photocatalytic reaction;after photocatalysis for 2 h,the characteristic peak of MB is destroyed.